Mixer



y 1, 1965 R. SLUIJTERS 3,182,965

MIXER Filed Oct. 6. 1960 I l6 W I INVENTOR.

ROBERT SLUIJTERS ATTORNEYS United States Patent M 16 Claims. (Cl. 2s9- 4 This invention relates to a liquid mixer, and relates more particularly to a liquid mixer having no movable parts and which is made up of a plurality of elements connected together to form the mixer.

Liquid mixers of the type with which the instant invention is concerned comprise a supply element, a discharge element and at least two mixing elements in between the supply element and the discharge element, with at least two channels formed by and running through said mixing elements. The arrangement of the'exits of the mixing elements is different with relation to each other than the arrangement of the entrances so that each of the channels running through each mixing element lies, seen in the direction of the flow of the materials being mixed, in the prolongation of at least two channels in each preceding mixing element.

Mixers assembled from identical and single mixing elements stacked together, heretofore employed, suffered from the disadvantage that the mixing elements could only be loosely stacked Within the mixer casing; accordingly, it was difiicult to prevent leakage streams inside the mixer itself. As a consequence thereof fractions of the liquids to be mixed did not follow the desired I paths of flow through the channels and in this Way formed poorly mixed portions in the finally mixed stream. Furthermore, the leakage streams in the mixer also resulted .in leakage from the inside of the mixer to the outside thereof.

A special disadvantage may result from said leakage streams when mixing liquids of which the chemical composition changes in the course of time. This occurs, for example, when mixing viscose. In case the leakage streams are faster than the mixing streams then layers of liquid with a decreased ripeness will be obtained. Most times, however, the leakage streams are very much .material which were tightened against the mixing elements. Notwithstanding the fact that this gave a very complicated construction, there still occurred leakage to the outside or along the mixing elements, and especially between the dividing surfaces of said mixing elements.

It is an important object of this invention to provide a liquid mixer which will be free from the foregoing and other disadvantages and which will be especially simple in construction and eflicient in operation.

Another object of this invention is the provision of an improved liquid mixer wherein a plurality of mixing elements are assembled in a cylindrical pipe in such a manner that leakage within the pipe and to the outside of the pipe is prevented without the necessity of heavy constructions or high sealing forces. i

Still another object of this invention is the provision of novel mixing elements adapted to be employed within a cylindrical pipe to form the liquid mixer.

3,182,965 Patented May 11, 1965 A further object of this invention is the provision of novel mixing elements made of elastomeric material.

Another object of this invention is the provision of novel mixing elements made of rubber.

The foregoing objects are attained by employing mixing elements of synthetic or natural elastomeric materials, which are fixed in a cylindrical pipe while being upset in an axial direction and which have a closed cylindrical outer mantle or periphery, adapted to fit slidingly into a pipe, within which closed outer mantle are contained channels for the passage therethrough of the liquid materials to be mixed. With this construction, no extraneous sealing of the pipe wall and mixing elements is necessary.

The result of the upsetting of the elastomeric mixing elements is that they seal against each other and that they press against the inside wall of the pipe containing the same to such an extent that the outer mantles of the mixing elements form a completely liquid-tight seal with said wall.

It has been surprisingly noted that the sealing becomes better as the liquid pressure in the channels increases. This is to be attributed to the fact that on account of this increased liquid pressure the contact surfaces of the mixing elements appear to be pressed against each other still more firmly.

It has been found that mixing elements manufactured from elastomeric material, particularly rubber, provide a satisfactory sealing with a smaller upsetting force than is the case with mixing elements made from other materials.

A possible explanation for this phenomenon may be that the upset elements hardly may deform any further as a result of an interior liquid pressure in the channels and consequently transmit the liquid pressure as if the elastomeric material itself were a liquid. As a result the liquid will 'not be able to develop leakage slits between the mixing elements. A consequence of this is that the mixer may be of a lighter construction and still be able to transmit the smaller upsetting force onto the mixing elements. The shape of the outer mantle of the mixing elements and of the inner wall may be cylindrical with different shapes of the cross-section. The shape of the cross-section may be square or rectangular dependent upon the course and the shape of the channels.

Accordingly, to this invention, however, it is preferred to give the outer mantles of the mixing elements and the pipe the form of a circular cylinder. As a result of the circular shape of the outer mantle the mixing element will more uniformly expand in all cross directions during the application of the upsetting force, and will therefore lay itself also uniformly against the inner wall of the case. Moreover, it has been found that the mixing elements are more stable in shape in case the outer mantle has a circular cylindrical shape. V

The pipe may be manufacturedfrom commercially available precision pipe, whereby the diameters of the pipe and of the outer mantle simply may be so chosen in advance that the desired sealing and the joining all around against the pipe is already obtained with a low upsetting force.

Although a sealing between the mixing elements is well possible in case the end surface of said mixing elements are flat, it is found, according to this invention, preferable to provide said end surfaces with projecting contours around the ends of the channels. By having said projecting contours, only said contours need to be sufficiently flat for obtaining a satisfactory sealing but, need not be perfect y flat in order to obtain a satisfactory sealing. This may be attributed to the fact that the projecting contours are more strongly deformed and pressed against each other with a smaller upsetting force than would be the case if the complete surface would lie against each other. By providing the projecting contours around the channel ends, dead corners are avoided in the channels through the mixer.

In order to be able to assemble the elements in the correct position relative to each other, according to the invention the end surfaces are preferably provided with bosses and corresponding recesses. In some cases, however, it has been found that it does not require exact positioning of the mixing elements relative to each other to cause the bosses of one mixing element to enter the corresponding recesses of the other mixing element. This can take place since the mixing elements are manufactured from a soft elastomeric material. The boss and the recess deform to such a degree that they will fit into each other even if they are somewhat out of line with each other. Where a partial overlapping of the projecting contours occurs, large dead corners will occur between the mixing elements and liquid may accumulate in said corners. This disadvantageous overlapping or out-of-line assembly of the mixing elements will not occur if the mixing elements are provided with V-shaped grooves in longitudinal direction at one or more points in the outer mantle thereof and round guiding rods are provided through said grooves throughout the complete case. These rods will elastically deform the mixing elements in said groove. In case the mixing elements are pushed along said guiding rods into the case an incorrect position of said elements relative to each other cannot occur. As a result of the small elastic deformation in the grooves the mixing elements can only be pushed into the interior and into the correct position along the guiding rods.

Additional objects and advantages of this invention will be apparent from the following description, and from the drawings in which:

FIGURE 1 is a view, partly in section, of the liquid mixer of this invention, without the mixing elements, showing in detail the end construction, it being understood that both end constructions are similar,

FIGURE 2 is a view taken on line 2-2 of FIGURE 1 in the direction of the arrows showing the end flange,

FIGURE 3 is a front view of a mixing element,

FIGURE 4 is a vertical sectional view of the mixing element shown in FIGURE 3, and

FIGURE 5 is a rear view of the mixing element shown in FIGURE 3.

Like reference numerals indicate like parts throughout the drawings.

Referring now to the drawings for a detailed description of this invention, the reference numeral 1 indicates a housing in the form of a cylindrical pipe. At each end of pipe 1 is suitably fixed, as by welding, a flange such as flange 2 and flange 3, and to these flanges are attached end flanges 7 and 6, respectively. Since the end flange constructions are alike only one, namely end flange 6, will hereinafter be described as mounted on flange 3.

Flange 3 is provided with a series of holes, preferably eight in number, each of the holes being equidistant from each other and on a circle concentric with the circumference of the flange. The said holes in the flange are alternately smooth bored, as shown at 4 in FIGURE 1 and threaded as shown at 5 in the same figure. The end flange 6 is fitted on flange 3 by means of interlocking edges and is provided with a series of holes 8 and 9 which in the assembly of flange 3 and end flange 6 are aligned with holes 4 and 5, respectively, of the flange 3. The holes 4 and 9 are adapted to receive bolts (not shown) serving to fasten to the mixer supply or discharge lines (not shown). For this purpose the said lines are provided with flanges having holes which in the assembled arrangement are in alignment with holes 4 and 9. The inner diameters of the said supply and discharge lines are of the same diameter as the circular portion of passageway 11.

The holes 8, as is evident in FIGURE 1, are so tapered or countersunk that the end flange 6 can be drawn against the flange 3 by means of a bolt 10 having a conical head when the said bolt is screwed into hole 5 of the said flange. The end flange is provided with a central passageway 11 which is smaller than the inner diameter of the pipe 1. This construction enables a series of mixing elements to be locked within the pipe 1 between the end flanges 6 and 7.

It will be noted from FIGURE 2 that the central passageway 11 changes in a longitudinal direction from a square shape to a circular shape, the square shape being directed towards the center of the mixer.

The end flanges 6 and 7 are also provided with two holes 12 and two holes 13 which are of smaller diameter than holes 12. Fitted between holes 13 of the end flanges are rods 14, only one of which is shown in FIGURE 1. The rods 14 lie diametrically opposite to each other within the pipe 1 against the inner wall thereof and in the direction of the longitudinal axis of the pipe. Normally eighteen mixing elements are positioned within the pipe to form the mixer, but it will be understood that any desired number of mixing elements may be employed in the mixer of this invention.

Of the eighteen mixing elements generally employed in the mixer, half the number, or nine, are of the structure of the mixing element shown in FIGURES 3, 4 and 5, while the remaining nine are constructed symmetrically opposite thereto relative to a longitudinal section. The mixing elements are arranged in the pipe so that they alternate.

The mixing elements, which will now be described with particular reference to FIGURES 3, 4 and 5, are molded from any suitable natural or synthetic elastomeric materials, particularly those having a very small volume elongation, rubber being preferably employed. Where the liquid to be mixed is caustic alkali, the material of the mixing elements should be natural rubber, preferably with a hardness of to Shore, and where the liquid to be mixed is acidic an acid-resistant synthetic rubber should be employed for the making of the mixing elements.

The elastomeric material is shaped to the desired form of the mixing elements by the use of suitable pressing or casting molds.

The mixing elements comprise circular cylindrical blocks having openings or channels 15 and 16 extending therethrough in a substantially longitudinal direction. These channels narrow first in the same direction but in opposite sense, and then widen in a cross direction, again in the same direction but opposite sense. In the outer diameter or mantle of the mixing elements, which diameter is slightly less than the inner diameter of the pipe 1 whereby the mixing elements fit slidingly in the pipe, there are provided two notched-shaped longitudinal grooves 17, 18. These grooves are diametrically opposite to each other and their shape is such that the material of the mixing element deforms elastically to a slight extent when they are assembled in pipe 1 along rods 14 which are adapted to be received in said grooves for positioning the mixing elements within the pipe.

The end surfaces of the mixing elements are provided with projecting contours 19 and 20 which frame channels 15 and 16. These projecting contours are substantially square in outline and when the successive mixing elements are assembled in the pipe they lie against each other with the projecting contours of the end mixing elements cooperating with square edge 21 formed in end flanges 6 and 7.

Each mixing element is provided on one end surface with bosses 22 and 23 and on the other end surface with recesses 24 and 25. With the aid of these bosses and aisaeea length of the row of mixing elements assembled in the pipe, the said length being measured between the extreme piojecting contours 19 and 29 on the end mixing elements. Accordingly, on assembling the mixer, the mixing elements are upset in an axial direction during the tightening of bolts it which causes end flanges 6 and '7 to be forced against flanges 3 and 2, respectively. Simultaneously with the upsetting of the mixing elements, the mixing elements are clamped tightly in a radial direction against the inner wall of pipe 1. In this manner an especially satisfactory sealing is obtained between the mixing elements themselves as well as between said mixing elements and the wall of the pipe.

The assembling of the mixer is very easily done since the mixing elements fit slidingly in the case when not upset and therefore may be simply pushed inside one after another.

The mixer of this invention is very efficient when mixing highly viscous liquids, such as viscose.

It is to be understood that various modifications relative to the embodiment described are possible without aifecting the scope of the invention. The various dimensions may thus deviate from those of the embodiment given. The ratio between the length and the diameter of the mixer may be varied within wide limits, whereas at the same time the number of the mixing elements may then be varied. In this manner any degree of fineness of mixing may be obtained.

What is claimed is:

1. In a liquid mixer without movable parts including a pipe having a supply opening and a discharge opening and at least two mixing elements, in abutting relationship, provided with end surfaces between said openings, each of said mixing elements having at least two channels therethrough, the improvement which comprises forming said mixing elements from an elastomeric material.

2. A liquid mixer according to claim 1 wherein the mixing elements are made of rubber.

3. A liquid mixer according to claim 1 wherein the mixing elements are provided at their end surfaces with projecting contours.

4. A liquid mixer. according to claim 1 wherein the mixing elements have a closed cylindrical outer mantle with said channels passing through the mixing elements within said outer mantle.

5. A liquid mixer according to claim 4 wherein the outer mantle of the mixing elements slidingly fits within the pipe, and the mixing elements in the pipe are arranged in an axial direction.

6. A liquid mixer according to claim 4 wherein the outer mantle of the mixing elements is provided with grooves and the pipe is provided with guiding rods which cooperate with said grooves to hold the mixing elements in position, said mixing elements thereby being slightly deformed in the vicinity of said grooves.

7. In a liquid mixer without movable parts including a pipe having a supply opening and a discharge opening and at least two mixing elements, provided with end surfaces, between said openings, the improvement which comprises said mixing elements being made of rubber and having at least two channels therethrough, each of said channels being provided with an exit and an entrance, the construction of said exits being different in size than the corresponding entrances, said mixing elements being disposed such that the exits of the channels in each mixing element are adjacent the entrances of the channels of the adjoining mixing element in overlapping relationship, the adjacent exits and entrances of every two adjoining mixing elements being arranged in a mutually abutting relationship so that each exit is in fluid flow relationship with the entrance of the channel of the adjacent mixing element, whereby each of said channels lies, taken in the direction of the flow of the liquid through the mixer, in the prelongation of each of said channels in the preceding mixing element.

8. A liquid mixer according to claim 7 wherein the mixing elements are provided at their end surfaces with projecting contours.

9. A liquid mixer according to claim 7 wherein the mixing elements have a closed cylindrical outer mantle with said channels passing through the mixing elements within said outer mantle.

10. A liquid mixer according to claim 9 wherein the outer mantle of the mixing elements slidingly fits within the pipe, and the mixing elements in the pipe are arranged in an axial direction.

11. A liquid mixer according to claim 9 wherein the outer mantle of the mixing elements are provided with grooves and the pipe is provided with guiding rods which cooperate with said grooves to hold the mixing elements in position, said material mixing elements thereby being slightly deformed in the vicinity of said grooves.

12. in a liquid mixer without movable parts including a pipe having a supply opening and a discharge opening and at least two mixing elements, provided with end surfaces, between said openings, the improvement which comprises said mixing elements being formed of an elastomeric material and having at least two channels therethrough, each of said channels being provided with an exit and an entrance, the construction of said exits being different in size than the corresponding entrances, said mixing elements being disposed such that the exits of the 7 channels in each mixing element are adjacent the entrances of the channels of the adjoining mixing element in overlapping relationship, the adjacent exits and entrances of every two adjoining mixing elements being arranged in a mutually abutting relationship so that each exit is in fluid flow relationship with the entrance of the channel of the adjacent mixing element, whereby each of said channels lies, taken in the direction of the flow of the liquid through the mixer, in the prolongation of each of said channels in the preceding mixing element.

13. A liquid mixer according to claim 12 wherein the mixing elements are provided at their end surfaces with projecting contours.

14. A liquid mixer according to claim 12 wherein the mixing elements have a closed cylindrical outer mantle with said channels passing through the mixing elements within said outer mantle.

15. A liquid mixer according to claim 14 wherein the outer mantle of the mixing elements slidingly fits within the pipe, and the mixing elements in the pipe are arranged in an axial direction.

16. A liquid mixer according to claim 14 wherein the outer mantle of the mixing elements are provided with grooves and the pipe is provided with guiding rods which cooperate with said grooves to hold the mixing elements in position and to deform the material mixing elements in said grooves.

References Cited by the Examiner UNITED STATES PATENTS 1,927,947 9/33 Newell 138-42 X 2,090,727 8/ 37 Gosmann.

2,633,343 3/53 Aghnides. 2,661,194 12/53 Katovsich 259-*4 X 2,664,109 12/53 lager -L. 13842 2,740,696 4/56 Longwell 259-4 X 2,890,868 6/59 Potchen 259-4 CHARLES A. WILLMUTH, Primary Examiner.

H. L. MARTIN, I. S. SHANK, Examiners. 

1. IN A LIQUID MIXER WITHOUT MOVABLE PARTS INCLUDING A PIPE HAVING A SUPPLY OPENING AND A DISCHARGE OPENING AND AT LEAST TWO MIXING ELEMENTS, IN ABUTTING RELATIONSHIP, PROVIDED WITH END SURFACES BETWEEN SAID OPENINGS, EACH OF SAID MIXING ELEMENTS HAVING AT LEAST TWO CHANNELS THERE- 